1. Field of the Invention
This invention relates to electronic circuits, and more particularly, to the calibration of resistive-capacitive (RC) time constants for electronic circuits.
2. Description of the Related Art
An RC time constant is a value, measure in units of time, indicating the amount of time required to charge a capacitor to approximately 63.2% of its full charge through a resistor. For an integrated circuit (IC) or various circuits thereof, an RC time constant can be a very important parameter affecting the operation of various circuits therein. For example, an RC time constant can affect switching times of some circuits, determining the amount of time required to switch from a first state to a second state in digital circuitry.
A simple way to measure an RC time constant is to measure a resistance, measure a capacitance, and multiply the two together. The product results in the RC time constant. The obtained RC time constant may be used to determine various performance metrics of the circuitry from which the reading is obtained. In some cases, the RC time constant may be calibrated by implementing variable resistances and capacitances in the circuitry (e.g., an IC) to which it applies.